Refrigerant system and apparatus



Dec. 7, 193 7.

M. A. MARTIN.

REFRIGERANT SYSTEM AND APPARATUS Filed Sept. 24, 1935 2 Shets-Sheet 1 INVENTOR.

lVzc/me/ A. Marfm.

ATTOR:NEYS

Dec. 7, 1937. M. A. MARTI N REFRIGERANT SYSTEM AND APPARATUS Filed Sept. 24, 1935 2 Sheets-Sheet 2 INVENTOR.

Patented Dec. 7, 1937 r I UNITED STAT-ES.- PATENT 0FFI-CE REFRIGERANT SYSTEM AND arrana'rus Michael A; Martin, Eric, Po. Application September 24, 1935, Serial No. 41,911

- 6 Claims. (Cl. 62-101) This invention relates to refrigerant systemsthat there is little tendency for a moving body of and apparatusembodying a liquid heat transliquid to freeze except under extreme conditions fer agent, and more particularly to improved. '0! temperature and at a considerably lower temmeans effecting circulation of such heat transperature' than the freezing temperature for a fer agent. J

Prior refrigerant systems adapted primarily to The cooling systems for milk usually comprise cool liquids such as beer, milk, and the like, with a heat insulated tank equipped with an evaporator which I am familiar, employ a heat insulated adjacent one or more sides of the tank, and since cabinet and a liquid container such as coils, tanks, the milk is to be cooled in cans rather than disor similar container disposed therein, through pensed as in a cooling apparatus for beer, the 10 which thehqllid b cooled l8 l w d or s or usual practice is to form ice on the evaporator T e e t a s may comprise ice pac d coils and place the cans of warm milk at subaround the coils or container, or a refrigerant sys-v stantially body temperature, or 96, therein. An such as the ss -ec d s r typ anti-freeze solution acts as the heat transfer wherein an evaporator is disposed in a cabinet agent between the evaporator and the milk. 15 through which a. volatile refrigerant'fluidisforced However, a considerable period is required to by the P SO I eit er case. for eihc e t lower the temperature of the milk to a desired operation, a heat transfer agent is necessary and pointzsuch as 40, due to the fact that a consider- W h al y mprises water or an anti-freeze ably greater number of heat units must be exsolution substantially immersing the container for acted from ilk to lower its temperature a 20 t q d to be 000186- given amount than a similar amount of water, and

TI find that the emciency of both Y secondly, due to the lack of circulation of the tems is considerably impaired e t the a of anti-freeze solution resulting 'inrelatively warm circulation of the heat transfer agent. A syssolution urrounding th lk n for conte emr oyinc ice s t e e l m s depends siderable period. This condition as to the time 25 up t e water associated therewith o extract involved in cooling is particularly undesirable in heat from. the liquid passing through Stored milk since the bacteria count builds up rapidly in the container and transfer the same to the ice. at high temperatures, and the bacteria, count n in such a system, the relatively colder water will be minimized if the milk is quickly reduced t a drop to the base of the cabinet and tend to redesired 10w wmpemtura 30 main there, rather than being continuously cir- I have devised a relatively simple f rced a is necessary emcient cooling t tern of circulation for the liquid heat transfer hquidagent hereinbefore described, which requires rela zraizsszaia'zzt We may be 3,, rate, the anti-freeze solution attains a higher 32 2 2 2};z zg i tg fifii g 33522 35: temperature, causing the thermostat control to a l d 1 maintain the compressor operating for longer inmatic system may operate on y ur ng pen tervals or at an increased speed resulting m a when the compressor is operative, or may operate independently,

40 relative] cold tem rature in the lower rtion of i the soluiion since the expansion of the refrig- In employing such a system I effect substari' erant fluid normally takes place in the lower constant temperature throughout W cab d theevapomtor and also due to the f t net, preventing ice formation on theicoiis, increasthat the solution has a greater density in the mg t efficiency of t refneerant 5ytem lower portion thereof due to unsaturated salt such many. and at g the ot e C0nd1t 0 s deas calcium-chloride or the like. This frequently fi effecting freezing 01 beer hd t g results in freezing the beer in the coils and con-- the Pipessequentlyrendering the system inoperative and in Normally, i i p n r, it is wi hdrawn some instances causing bursting of the coils. from the Container after P s through a a.

Additionally, d e t la k of i l t i y ofrelatively warm water, resulting in the beer 50 form on the evaporator coils and also on the bevbeing dispensed Substantially at the temperature erage coils, forming heat insulation and greatly of this water. This temperature is higher than impairing the efficiency of the system. Proper desired, since warm beer is relatively unpalatcirculation of the liquid heat transfer agent would able, whereas if the beer were dispensed at the A5 eliminate this ice formation, since it iswell known average temperature 'of the heat exchange static body of the same liquid. 5

liquid, as would be effected by proper circulation, it would be considerably more palatable.

Automatic refrigerant systems, such as those employing a volatile refrigerant fluid passing through an evaporator, may be thermostatically controlled and operate in a well known manner to effect a heat exchange between the liquid in the container .and the evaporator through the medium of a liquid heat transfer agent. This heat transfer agent is usually an anti-freeze solution such as water and calcium-chloride or the like.

It is a primary object of my invention, therefore, to provide improved circulating means for a liquid heat transfer agent.

Another object of my invention is to provide means in a refrigerant system for beverages whereby the temperature of the beverage is maintained more nearly uniform in a given interval than in prior systems with which I am familiar.

Another object ofmy invention is to provide improved means efiecting circulation of a liquid heat transfer agent in a refrigerant system, thereby increasing the efflciency of the system, whereby a relatively smaller unit may be employed.- 4

Another object of my invention is to provide improved circulating means for a liquid heat transfer agent in a refrigerant system whereby the formation of ice on the refrigeration evaporator will be prevented.

Another object of my invention is to provide an apparatus effecting circulation of a liquidheat transfer agent in a refrigerant system adapted to either an ice system or an automatic mechanical system, and which is adjustable to accommodate cabinets of varying dimensions.

Other objects of my invention and the invention itself will become. increasingly apparent from a consideration of the following description and drawings, wherein:

Fig. 1 is a sectional elevational view, showing my invention incorporated in an automatic refrigerant system associated with a beer or sun ilar beverage dispensing apparatus;

Fig. 2 is a sectional elevationalview showing my invention embodied in a beer or similar bev-- erage dispensing apparatus, wherein ice is employed as the cooling means;

Fig. 3 is a view generally similar to Fig. 1, showing a modification of my invention incorporated in a beverage dispensing and cooling apparatus employing an automatic refrigerant sys- Fig. 4 is a. sectional elevational view showing my invention incorporated in an automatic refrigerant system adapted to cool milk or similar .lineB-SofFig.

fluids; and

Fig. '5 is a sectional view taken along the line 5-5 oLFig. 1; and

Fig. 6 is a fragmentary view taken along the essential.

4 l zontal and vertical leg portions, indicated at ll are preferably immersed by an anti-freeze solution such as water and calcium-chloride, which eifectsa heat exchange between the coils and the evaporator and acts as a hold-over or heat storage medium during intervals when the compressoris not operating. As previously explained, the anti-freeze solution usually has a greater density in the lower portions of the cabinet and due to this factor; and the fact that liquid refrigerant entering the lower portion of the cabinet is quickly volatilized, the greatest heat exchange takes place in the lower portions of the cabinet, and the anti-freeze solution is relatively colder at this point. The warmer portion of the solution remains closest to the surface in the conventional systems, and little or no circulation is effected. This lack of circulation, as previously pointed out, may result in ice forming on the evaporator and beverage coils with resultant freezing of the beer and probable bursting of the coils, and even if this does not occur the efliciency of the system is impaired by the lack of circulation since the temperature of the upper strata of the anti-freeze has to be maintained substantially at the temperature or slightly lower than the withdrawal temperature of the beer,

thus maintaining the lower portion of the solution several degrees colder.

The operation of the compressor may be controlled in the usual manner by a thermostatic switch, generally indicated at [5, which is operably responsive to changes of temperature of a capillary tube 23 immersed in the anti-freeze solution. The tube is usually disposed adjacent the surface of the anti-freeze solution since the governing factor is the withdrawal temperature of the beer or beverage, and which is substantially that of the anti-freeze solution at the surface. The compressor unlt generally indicated at 24 is connected to the evaporator I2 by the usual refrigerant fluid supply and return lines 2411 and 241), the lines'being shown broken for convenience in illustrating. Thermostatic switches are well known and the switch 15 illustrated controls energizing of the compressor circuit from the power leads indicated at 21 and concurrently the circuit for a circulator to be hereinafter described. Gas pressure in tube 23 at a pre-determin'ed temperature effects movement of a bellows or the like and an associated electrical contact to close the circuit and at a pre-determined lower temperature contracting movement of the bellows opens the circuit. The temperature limits at which the switch operates may be adjusted by movement of a handle 28.

To eflectcirculation of the anti-freeze solution and maintain a substantially even temperature throughout the cabinet and a rapid exchange of heat between the beverage coils and the evaporator, I provide an apparatus called a circulator and generally indicated at 15.

The circulator comprises interconnected horiand I8 respectively. Both the horizontal portion l1 and the vertical portion I! are telescopviding an upward extension of the vertical portion I8 and securing the motor thereto, with the motor shaft 20 projecting downwardly into the vertical portion l8.

An'impeller 2| is rigidly secured to the end of the shaft 20. The motor l9 may be of relatively small horse-power since the impeller 21 does not have to lift liquid against any appreciable head, but merely to effect circulation of the same. It is understood that suitable packing or other means will protect the motor parts from liquid which might penetrate thereinto, and the motor may be mounted in this instance above the liquid level.

The anti-freeze solution will be drawn upwardly through the vertically extending portion l8 of the circulator conduit and discharged ,adjacent the surface of the liquid through the horizontally disposed conduit portion I'I. To effect the discharge of solution through the conduit portion I1 I provide a plurality of holes 22 preferably on the underside of the conduit portion I1,

these holes being sufllciently numerous and so spaced as notto interfere with the telescoping arrangement.

The motor I9 is controlled by a switch, generally indicated at 25. and which may be controlled jointly with the compressor by means of the thermostatic arrangement whereby the motor will be operative onlydurlng operative periods of the compressor, which is a preferred arrange-. mentsince the maximum refrigerating effect will take place during operation of the compressor. It

is necessary to effect circulation of the anti-freeze solution since the tendency for the beer to freeze and other difficulties previously mentioned will be greatest at this time. However, it is not necessary that the motor be controlled concurrently with the compressor, and'the switch 25 may be manually controlled rather than thermostatically, as desired by manipulation of a button 29.

The circulator may be supported in any suitable manner, and in the embodiment describedI provide generally channel-shaped clips 26 integrally secured to the vertically extending portion it of the conduit by soldering or the like, and secured to a wall of the cabinet by screws or similar means. I preferably secure the clips 26 to relatively telescopical portions of the conduit i8, permitting adjustment to cabinets of varying heights, and I preferably position the circulator so that the horizontally extending portion i1 passes over the central portion of each of the coils H, whereby the relatively cold solution forced upwardly from adjacent the cabinet base will pass through the perforations provided in the conduit portion-i1 to relatively cool and effect circulation of the warmer solution in the upper portion of the cabinet. 7

Although I have shown this embodiment of my invention as adapted to an automatic refrigerant system for beer, it is understood that it may be utilized with icepack systems and for cooling other liquid than beer.

Referring now to Fig. 2, I have illustrated another embodiment of my invention generally similar to that illustrated in Fig. 1, but adapted to ice as thefrefrigerating agent, and the position of the motor i9 is changed.

In this modification, the conduit is generall U-shape, comprising an adjustable horizontally extending upper portion 30, an adjustable horizontally extending lower portion 3| intercom nected by an adjustable vertically extending portion 32. The portion 30 is provided with a plurality of perforations 22 for a purpose previously described, and the lower conduit portion 3| may also be provided with a plurality of perforations to effect a more uniform circulation.

A motor IS in this instance is disposed horizontally and rigidly afflxed to an external wall of the cabinet with the motor shaft 20 extended through the insulation of the cabinet and projected into the lower conduit portion 31. Any suitable bearing and seal may be provided at 33 to prevent leakage around the motor shaft 20. n

v Fig. 3 illustrates another embodiment of my invention, generally similar to that illustrated in Fig. 1, but wherein the motor I9 is disposed externally of the cabinet and supported by a bracket or the like 40 afixed to the cabinet wall, the shaft 20 projecting through the wall insulation and mounted in a manner slmilanto that described in connection with the embodiment of .Fig. 2. In this modification the circulator circuit is controlled by a thermostatic switch l5 previously described and the compressor operation may be controlled independently of the circulator by a conventional switch responsive to refrigerant fluid pressure. 7

Referring toFig. 4, I have illustratedtanother modification of my invention generally similar to those described but adapted primarily to cooling milk. In this modification the cabinet is provided with suitable heat insulation such as cork or the like, the circulator tube being generally U-shaped. The circulator tube comprises adjustable horizontal upper and lower-portions 5i and 52 respectively interconnected by an adjustable vertical portion E3 disposed within the insulation. i

The motor is is preferably mounted on a shelf 56 provided on the cabinet and operates as previously described to actuate the impeller 2i and effect circulation through the U-shaped tube arrangement. Encasing the vertical portion 53 of the tube in the insulation minimizes any lossof heat by radiation.

The cans containing milk or the like are indicated at 55 and to effect a uniform circulation therearound I preferably construct the tube por- .ta'lly extending portions in the various modifications if desired, and the ends of such .portions' may be either entirely closed or restricted.

Although I have described the heat exchange I liquid as circulating from bottom portions of the cabinet upwardly through the tube, it is -understood that the direction of circulation may be reversed and'tlie heat exchange liquid caused to flow downwardly through the tube from top portions of the cabinet to lower portions.

Although I have shown and described modifications of my invention, I contemplate that numerous and extensive departures may be made therefrom without departing from the spirit of my invention and the scope of the appended r I claim:

1. The combination with a single heat insulated cabinet, a liquid container in the cabinet, means for cooling said container comprising a liquid heat transfer agent substantially immersing the container, of means effecting circulation 1 of the heat transfer liquid comprising a tube of a substantially uniform diameter having an open end adjacent the cabinet base and a perforated horizontally extending portion immersed by said heat exchange liquid, and disposed a substantial distance upwardly from the cabinet base, and

motor operable impeller means within the tube whereby the heat exchange liquid may be circulated through the tube from one portion of the cabinet to another portion, to maintain a substantially uniform temperature of the heat exchange liquid throughout the cabinet.

2. The combination as described in claim 1, and wherein said tube is horizontally and vertically adjustable to accommodate varying sizes of cabinets.

3. The combination with a single heat insu- 'lated cabinet, liquid containing means in the cabinet, automatic refrigerating means comprising an evaporator disposed in the cabinet and a compressor disposed externally thereof, liquid heatv transfer means substantially immersing the liquid container, means effecting circulation of the heat transfer liquid comprising a tube having an open end adjacent the cabinet base and a perforated horizontally extending portion nor-' mally immersed by said heat transfer liquid, impeller means projected within the tube where; by liquid will be continuously circulated through the tube to maintain a substantially uniform 0 temperature of the heat transfer liquid throughout the cabinet, and a common switch means controlling actuation of the compressor and impeller responsiveto temperature of the heat exchange liquid.

4. The combination with a single heat insulated cabinet, a liquid container in the cabinet, means for cooling said container comprising a liquid" heat transfer agent substantially immersing the container and normally of a lower temperature in .the lowermost zone of the cabinet, means eifecting circulation of the heat transfer liquids comprising a tube having an open end adjacent the cabinet base and a perforated horizontally extending portion immersed by said heat exchange liquid and adjacent to the liquid surface, a motor operable impeller projected within the tube and substantially rotatably engaging the inner walls of the tube, a rotary shaft inter-connecting the motor and the impeller of a length comprising a minor portion of its associated tube length, and an evaporator within the cabinet adapted to maintain the temperature of the heat transfer liquid below a predee termined value.

5. The combination with a single heat insulated cabinet, a liquid container in the cabinet, and-means for cooling said container comprising a liquid heat transfer agent substantially immersing the container, of means effecting circulation of the heat transfer liquid comprising a tube of substantially uniform diameter having perforated horizontally and vertically extending portions, the perforations in one portion being adjacent the cabinet base'and in the otherv portion being adjacent to but beneath the level of the liquid heat transfer agent, the vertical tube portion vbeing adjustable to accommodate cabinets of varying heights, and motor operable throughout the cabinet. 1

6. The combination with a single heat insulated cabinet, 9. liquid container in the cabinet and means for cooling said container comprising a liquid. heat transfer agent substantially immersing the container, of meansefiecting circuother portion to maintain a substantially uniform temperature of the heat. exchange liquid throughout the cabinet, and a thermostatic switch controlling operation of the impeller motor responsive to temperature of the heat exchange liquid in a given portion of the cabinet.

MICHAEL A. MARTIN, 

